<!DOCTYPE html>
<html>
  <head>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <style>
    body {
      margin: 0px;
    }

    iframe {
      position: absolute;
      width: 100px;
      height: 100px;
      border: none;
    }

    div {
      position: absolute;
      top: 0px;
      left: 50px;
      width: 100px;
      height: 100px;
      background-color: red;
    }
    </style>
  </head>
  <body>
    <iframe src="/cross-site/baz.com/title1.html" style="left:0px; z-index:-1"></iframe>
    <div style="z-index:0">I cover the left iframe but is covered by the right iframe.</div>
    <iframe src="/cross-site/bar.com/title1.html" style="left:100px; z-index: 1"></iframe>
  </body>
</html>
